Do you flash your headlights at oncoming cars to warn them of cop cars?

[GeorgiaModerate]

I've done it where there are unfair speed traps (e.g. the speed limit suddenly drops from 45 to 25 and the cop is hiding around the next bush).  I don't do it 100% of the time.

But a variant I do like: if I see an oncoming car speeding dangerously over the limit or weaving all over the road, I'll flash my lights even though there's no cop lurking, as a way to get them to slow down.